title: Pallidotomy suppresses beta power in the subthalamic nucleus of Parkinson's disease patients.
abstract: Parkinsonian patients, who have had a unilateral pallidotomy, may require bilateral deep brain stimulation of the subthalamic nucleus (STN), due to disease progression. The current model of the basal ganglia circuitry does not predict a direct effect of pallidotomy on the neuronal activity of the ipsilateral STN. To date, only three studies have investigated the effect of pallidotomy on overall activity of the STN or neuronal firing rate, but not on the spectral content of the neuronal oscillatory activity. Moreover, none of these studies attempted to differentiate the effects on the dorsal (sensory-motor) and ventral (associative-limbic) parts of the STN. We studied the effect of pallidotomy on spectral power in six frequency bands in the STN ipsilateral and contralateral to pallidotomy from seven patients and in 60 control nuclei of patients without prior functional neurosurgery, and investigated whether this effect is different on the dorsal and ventral STN. The data show that pallidotomy suppresses beta power (13-30 Hz) in the ipsilateral STN. This effect tends predominantly to be present in the dorsal part of the STN. In addition, spectral power in the frequency range 3-30 Hz is significantly higher in the dorsal part than in the ventral part. The effect of pallidotomy on STN neural activity is difficult to explain with the current model of basal ganglia circuitry and should be envisaged in the context of complex modulatory interactions in the basal ganglia.
authors.affiliation: Department of Neurology/Clinical Neurophysiology, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands. m.f.contarino@amc.uva.nl
authors.forename: Maria Fiorella
authors.initials: MF
authors.lastname: Contarino
authors.forename: Lo J
authors.initials: LJ
authors.lastname: Bour
authors.forename: Maarten
authors.initials: M
authors.lastname: Bot
authors.forename: Pepijn
authors.initials: P
authors.lastname: Van Den Munckhof
authors.forename: Johannes D
authors.initials: JD
authors.lastname: Speelman
authors.forename: P Richard
authors.initials: PR
authors.lastname: Schuurman
authors.forename: Rob M A
authors.initials: RM
authors.lastname: De Bie
mesh_terms: D000368:Aged; D046690:Deep Brain Stimulation; D018450:Disease Progression; D004594:Electrophysiology / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009474:Neurons / Q000502:physiology*; D053860:Pallidotomy / Q000009:adverse effects*; D010300:Parkinson Disease / Q000503:physiopathology* / Q000601:surgery*; D012189:Retrospective Studies; D020531:Subthalamic Nucleus / Q000166:cytology / Q000502:physiology* / Q000503:physiopathology*